I think his point really is, though, that he didn't get a -1 for a downvote on the primary site, which is a no-repro from my end. I cast a downvote on Gaming and got the -1.
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squillmanJul 12 '10 at 4:35

The post in question was community wiki - I didn't realize that until just now. Downvoting does work as intended on the parent site. This answer is still helpful as I was confused about why my reputation wasn't changing on Meta.
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CoreyJul 12 '10 at 4:41